Process for pentaerythritol-degummed soybean oil-modified alkyd resins



, wherein degummed soybean is c ole nate were used in the conventionalmane Patented May 5, 1953 PRUCESS FOR PENTAERYTHRITOL-DE- GUMMED SQYBEANGEL-MQDIFKED ALE'EZD RE SINS Paul E. Elias-ling and August Hernpcl,Dayton,

Qhic, assignors to Monsanto Chemical Company, St. Louis, Mo, acorporation of Delaware No Drawing.

Application ll larch 27, 1956,

7 Claims. 1

This invention relates to a process for the pro duction oil-modifiedpentaerythritol type alkyd p in place of the conventional al.l:ali-reiined s ybean oil.

The alkyd resin art is very voluminous and the industry is keenlycompetitive. Hence, any irnmovements in characteristics or econom cs oithe alkyd resin products are extremely ogeous. Therefore, attempts havebeen made to replace alkali refined soybean oil with the chea erdesummed soybean oil. It was found that when tnormal procedures of theprior art were employed, wherein oil-soluble alcoholysis catalysts, asfor example, calcium naphthenate and zinc naphtbecoholysis was notaccomplished in a reassess prc-ccs no time, but ultimately whenalcoholysis was attained the resultant alkyd resin products contained alarge quantity of a flocculent su pension which was extremely diflcultor impossible to filter. This problem appears to be unique withpentaerythritol type alkyds since glycerol t alkyds do not exhibit thisphenomenon.

The formation of this gelatinous precip not fully understood, but itappears certs it is related to the extraneous matter found in degummedor clarified soybean oil. The break. of crude soybean oil containsphosphatides, pigements, proteins or protein fragments, mucilaginousmaterials and varying amounts or these materials are retained in thedegun ed oil. The principal detrimental material is believed. to be thephosphatides which are glycerophosphoric acid esters, as for example,lecithin and cephalin. The degummed or clarified soybean oil has a ntialportion of the break eliminated by treatment with water, wherein the waer and crude oil are brought into intimate contact by emulsifying themtogether and then holding them for a suitable time to effect hydrationof the bre material components causing their precipitation. and enablingtheir removal by centrifugaticn or other suitable methods. Accordingly,degummed soybean oil can be defined as raw or crude soybean oil fromwhich only a portion of the brealr material components have beenremoved. Crude oil from the mechanical processes, expeller, screw pressand hydraulic press, contain larger amounts of break materials thansolventextracted oils and generally require a desiunmihii treatmentbefore being applicable to utilization in the process of this invention.Several of the itaie is as ior example,

solvent-extraction processes entail steaming of the break materials andprovides an oil which may be oirec'tly used in this invention.

most purposes the dcgumined soybean oil requires additional refining tofurther reduce the extraneous components of the oil. A large portion ofthe commercial soybean oil is alkalireiined, wherein the oil is heatedwith an excess -tic soda suincient to neutralize the free fatty acid,remove the break and reduce the color. oil is then allowed to separateand the oil phase well washed with water to provide an ash- ;reep.:oduct. Then the oil is vacuum dried in a spray chambc to effect rapidremoval of the moisture to prevent hydrolysis of the oil. Obviously, theadditional processing of an alkalisoybean oil is reflected in itsselling price which range from about 8 to 12 per cent greater than aclarified oil.

It is principal object of this invention to provide a process for theproduction of oil-modifled. pent-aerythritol type alkyd resins utilizingdegu..- ned soybean oil. Another object is to enable the production ofdegummed soybean oilied alkyd resins without poisoning the alcoholysiscatalyst. ther objects will be apparent to those skilled in the art.

It has now been found that a pie-treatment of degurnmed soybean oil withpentearythritol for at least about 10 minutes at above about 450 F.enables the further processing or the degummed soybean oil in theconventional manner with a normal alcoholysis time and a reduction ofthe gelatinous precipitate enabling the ready filtration oi the product.When pure mono pentaerythritol is employed, a clear alkyd resin is directly obtained.

It believed that the short pre-treatment oi the degummed soybean oilwith pentaerythritol causes an esterification of the phosphatidespresent in degulnmed oil thereby solubilizing the phosphatides in thealkyd resin product and chi-.- inatins or reducing precipitation. Thisprocedure also eliminates potential point of reaction of -.olublemetallic alcoholysis catalyst, wherein, for example. the calcium saltsof the in. a normal manner.

It is possible to remove the phosphatides incorpora-tas sufficientcatalyst to neutralize same and then the desired excess of catalyst foralcoholysis. This procedure is, however, uneconomical and impractical,sin ,e a relatively large amount of catalyst may be required and theresultant product would contain a dimcultly filterabie precipitate.Further the stoichiometric reslightly hazy but was easily filtered to 2.

A closed reaction vesselwas adapted to exclude oxygen from the system byproviding a-positive pressure flow of carbon dioxide during thereaction. The vessel was also equipped to provide rapid agitation.

A 137.5-g. sample of regummed soybean oil was charged into the reactionvessel, the flow of carbon dioxide initiated "and the oil heated to 480F. Then 13.8 g. of pentaerythritol (technical) was added and heatingcontinued for about 17 minutes at which time0.-57 g. of a calciumnaphthenate solution containing per centcalcium was added. After 22minutes at about 475 F. an

additional 15.0 g. of pentaerythritol was introduced and alcoholysiscontinued for 21 minutes at which time the methyl alcohol test indicateda solubility of 4 parts of alcohol per part of product at the boilingpoint of this mixture. 51.9 of phthalic anhydride and'1.06. g: ofmal'eic anhydride were added and a temperature of 450 F. maintainedduring esterification. Ten minutes after the temperature reached 450 F.0.75 ml.

of triphenyl phosphite was added. After a total...

time of esterification of about 3 hours, the alkyd resin had an acidvalue of 8, a Gardner-Holdt viscosity of U when made up as a '70alkydmineral spirits formulation and the product was product.

Example 2 A 134.8-g. sample of degummed soybean oilwas added to thereaction vessel of Example 1, the

flow of carbon. dioxide initiated, and the oil heated to 480 F. lhen27.2 g. or" pentaerythritol (technical) was added thereto. After 15minutes, 0.66 g. of a calcium naphthenate solution contain ing 5 percent calcium was added and alcoholysis of the oil was discontinued after32 minutes at 480 F., at which time the methyl alcohol solubility was 4parts of alcohol per part of the product at the boiling point of thismixture. Then 53 g. of phthalic anhydride and 1.2 g. of maleic anhydridewere added and a temperature of 450 Example 3 A similar experiment toExample 1 was run but the degummed soybean oil, pentaerythritol andcalcium naphthenate were reacted together rather than first interactingthe degummed soybean oil and pentaerythritol.

A 137.5-g. sample of degummed soybean oil was added to the reactionvessel of Example 1, the flow of carbon dioxide initiated, and the oilheated to 480 F. The calcium naphthenate catalyst (0.57 g.) andpentaerythritol (13.8 g.) were clear;

Then

-steps.

stepwise addition process as indicated above in added and heatingcontinued at about 475 to 480 F. for about an hour, at which time thereaction mixture was still cloudy, indicating that appreciablealcoholysis had taken place.

As shown in Examples 1 and2 above the pentaerythritol can be addedstepwise or all at once. When only a portion of the totalpentaerythritolis added and reacted with the degummed soybean oil prior to the additionof the catalyst, it is preferred that about 10 per cent by weightb'ased'on the oil be employed, then after the addition of the catalystand after the alcoholysis has progressed for a short time the balance ofthe pentaerythritol can be added in one or more It is generallypreferable to employ the order to provide alkyd resin products of lightcolor, particularly when medium and short oilmodified alkyd resins areproduced.

When pure mono pentaerythritol was employed a clear resin was directlyobtained as described and claimed in the copending application of PaulMarlins and August-R. Hempel, Serial No. 152,011, filed March 25, 1950.

The catalyst concentration preferably employed, expressed as themetallic element component, is from about 0.01 to about 0.05 per cent byweight of the oil, but larger amounts may be employed. The alcoholysistemperature is preferably maintained at from about 450 F. to about 525F., and preferably the alcoh'olysis' product should show a solubility ofat least 2.5 parts by volume of methyl alcohol per part by volume ofproduct at room temperature before the addition of the dicarboxyllc acidanhydride.

The dicarboxylic acid anhydride should be selected from the groupconsisting of phthalic anhydiide and a mixture of phthalic anhydride andmaleic anhydride, wherein the latter does not exceed 15 per cent andpreferably does not exceed per cent by Weightofthe former. Theesterification temperature is preferably maintained at from about 4&0 toabout 525 F. for a sufiicient time to reduce the acid value to belowabout 15.

The invention herein disclosed is applicable to the entire range ofoil-modified alkyds, the above specific examples demonstrating theutility with a long, oil-modified alkyd. The general range of degummedsoybean oil which can be employed is from about to about per cent byweight of the total resin ingredients.

Preferably the alkyd resin should be treated with from about 0.2 toabout 2.0 per cent, by weight of the alkyd resin, of a phosphoruscompound, as for example, triphenyl phosphite and orthophosphoric acidto improve the resin color and avoid any opacity caused by the presenceor a dicalcium salt of the dicarboxylic acid anhydrides. This materialis generally added about 10 to 30 minutes after the esterificationreaction temperature reaches about 440 F.

It is understood that the alkyd resin may be formulated in the usualmanner, as for example, with solvent, pigments, fillers, and driers.

We claim:

1. In the process of producing a degummed soybean oil-modified alkydresin the step consisting of the reaction of pentaerythritol anddegummed soybean oil at a temperature above about 450 F. for at leastabout 10 minutes prior to the introduction of the oil-solublealceholysis catalyst, then adding the said catalyst and continuing thealcoholysis until a clear solubility at room temperature of at least 2.5parts by volume of methyl alcohol per part by volume of product isobtained, then esterifying the resulting product by adding adicarboxylic acid anhydride until the acid value is reduced below about15.

2. The process of producing a degummed soybean oil-modified alkyd resincomprising the reaction of pentaerythritol and degummed soybean oil at atemperature above about 450 F. for at least about 10 minutes then addingfrom 0.01 to about 0.05 per cent, expressed as the metallic elementcomponent, oil-soluble alcoholysis catalyst, based on the weight of oilemployed, and continuing the alcoholysis until a clear solubility atroom temperature of at least 2.5 parts by volume of methyl alcohol perpart by volume of product is obtained, the temperature for alcoholysisbeing maintained at from about 450 to about 525 F., then esterifying theresulting product by adding a dicarboxylic acid anhydride selected fromthe group consisting-of phthalic anhydride and a mixture of phthalicanhydride and maleic anhydride wherein the latter does not exceed 5percent by weight of the former and heating at from about 440 to about525 F. until the acid value is reduced below about 15.

3. The process of claim 2 wherein the catalyst 2 is calcium naphthenate.

4.. The process of claim 2 wherein the catalyst is zinc naphthenate.

5. The process of claim 2 wherein from about 30 to about 15 per cent, byweight of the total resin ingredients, is degummed soybean oil.

6. The process of claim 2 wherein from about 0.2 to about 2.0 per cent,by weight of the alkyd resin, of a, phosphorus compound from the groupconsisting of triphenyl phosphite and orthophosphoric acid is added tothe reaction mixture at about 10 to 30 minutes after the esterificationreaction temperature reaches about 440 F.

7. The process of claim 2 wherein about 10 per cent pentaerythritol, byweight based on the oil, is reacted with the degu-mmed soybean oil priorto the catalyst introduction and the balance of a the pentaerythritol isadded thereafter.

Name Date Hubbuch et a1 Mar. 6, 1945 Marling Aug. 23, 1949 Number

1. IN THE PROCESS OF PRODUCING A DEGUMMED SOYBEAN OIL-MODFIFIED ALKYDRESIN THE STEP CONSISTING OF THE REACTION OF PENTAERYTHRITOL ANDDEGUMMED SOYBEAN OIL AT A TEMPERATURE ABOVE ABOUT 450* F. FOR AT LEASTABOUT 10 MINUTES PRIOR TO THE INTRODUCTION OF THE OIL-SOLUBLEALCOHOLYSIS CATALYST, THEN ADDING THE SAID CATALYST AND CONTINUING THEALCOHOLYSIS UNTIL A CLEAR SOLUBILITY AT ROOM TEMPERATURE OF AT LEAST 2.5PARTS BY VOLUME OF METHYL ALCOHOL PER PART BY VOLUME OF PRODUCT ISOBTAINED, THEN ESTERIFYING THE RESULTING PRODUCT BY ADDING ADICARBOXYLIC ACID ANHYDRIDE UNTIL THE ACID VALUE IS REDUCED BELOW ABOUT15.